Electromechanical device.



2 SHBBTSSHBET l.

Patented Apr. 23, 1912.

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G. H. ROWE.

{III il ELEGTROMI-JOHANIGA L DEVICE APPLICATION FILED MAY 18. 1910.

, H QMJ QQ 7 G. RG'WE, ELEOTBOMEGHANIGAL DEVICE. APPLIGATION PEI-ED M15118, 1910. 1,024,02 Patented Apr. 23, 1912 2 SHEBTS-SHEET 2.

'iLliIOBGE H. ROWE, OF BERWYN, ILLINOIS ,"ASSIGNOR TO ELECTED-MAGNETIC TOOL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS,

ELECTROM'EGHANICAL DEVICE.

Application flies tiny 1s, 1916. Serial No. 562,109.

To all whom it may concern This it known that I, Grouse H. Zen of the United States, residing at erwyn, in the county of Cook and i. tate of A Illinois, have invented certain new and use ful. Improvements in Electromechanical De-' vices, of which the following is a specification.

My invention relates to an electro-mei ohanical device of the general character of claimed.

and the driving means.

One of the primary objects of the invention is to provide an a1r cushion for the striking part which supplements the magnetic connection between the drlven element The invention has for further objects to strengthen, simplify, lighten, and generally to improve the constructions employed when my invention is embodied in a drill or similar percussion device.

The invention is illustrated in the accompanying drawings, in which- Figure 1 is a fragmentary longitudinal sectional view of an electric drill of the sort best shown in my Patent No. 938,709, above mentioned. Fig. 2 a view in perspective of the reciprocating sleeve. Fig. 3 a longitudinal sectional view of the same. sectional view taken on line 4-4- of Fig. 1, looking in the direction of the arrows. F 5 a similar view taken on line of Fig. 1. Fig. 6 a side view of the device for snpporting the crank shaft bearings of the drivingmeans. the pole pieces of the magnet. Fig. 8 a similar view of the tool-holding nose-piece, and Fig. 9 a plain view of the cap piece of the sleeve.

Like characters of reference indicate like I parts in the several figures of the drawings.

Specification of Letters Patent.

Fig. 4 a

Fig. 7 an elevation of one of Patented Apr. 23, 1912.

the driving gear. 13 is the head of the latter casing and is constructed referably with a central opening for the ba 1 bearing 14: of the armature shaft 15 of the motor. 16 is a bevel gear on shaft 15 which meshes with a bevel gear 17 on the crank shaft 18. The latter turns in ball bearings 19 which are sustained in the projecting bosses 20 on brackets 21 which are preferably formed integrally with the head 13. This arrangement protects the ball bearings of the crank shaft from dust and dirt.

The ball bearings 14 and 19 are of familiar construction and need not be described in detail.

23 represents the spool of the exciting coil designated by 24:. Theooil has two pole pieces, pole piece 25 at its inner end and pole piece 26 at its outer end, the latter formed integrally with the steel nose-piece 27 The pole pieces 25 and 26 are preferably formed with thecylindrical extensions 28, to increase. their effective area, the extension being preferably slotted at 28 to prevent eddy currents. Pole piece 26 screws 4 into the steel casing 29 which surrounds the coil 24, casing 29 being lapjoined with casing 12. The tie rods 30 extend through casing 29 into openings 25 in pole piece 25. The shank 31 of tool holder 32, which carries the drill tool 33 extends through a. tool steel socket piece 341 in the nut portion 35 of the nose-piece 27. I

' Within coil 24 is a sleeve 36,- preferably formed with the central openings 37. The sleeve is'connected with the crank shaft 18 by a connecting'rod 38, the connecting rod being secured to the sleeve by a pin 39, which latter is held in place by cotter pins 40. The

pin is also preferably used for securing to the sleeve the cap piece 41, designed to close the inner end of the sleeve so that the armature or plunger 42 is air cushioned. Preferably, the sleeve 36 is formed with the small openings 43 communicating with slots 44 in the outer surface.

41 is a wedge on the upper surface of cap piece 41 which spreads the ends of one of the cotter pins 40.

It is ordinarily believed that the armature of a solenoid should be made of soft iron because of the magnetic capacity of that metal. I have found byexperiment, however, that my armature or plunger 42 gives very good results trom'a magnetic point of view when made of hardened tool steel throughout; and the use of this metal makes this part of the device very durable.

Preferably, the wires 45, leading into coil 21, pass through bosses l5 on the pole piece 25. This construction is not claimed herein as it is made the subject matter of claims in my co-pending application, Serial No. 521,732, tiled October S, 1909.

Preferably, a thin brass sleeve it; is interposed bet-ween sleeve 36 and pole piece extension 28.

The operation of the device, as above described, is as follows: When the motor is set in operation, sleeve 36 is reciprocated and the magnetic attraction produced by coil 24 causes the armature or plunger .42 to follow the movements of the sleeve the plunger being held in floating relationship with the sleeve and out of contact with the cap piece 41. The plunger is therefore made to strike a series of blows against the shank 31 of the carrier 32 in which the drill tool mounted. The cap piece 41 forms an air cushion for the plunger l2 at the inner end of the sleeve. This air cushion supplements the magnetic connection between the sleeve and the plunger when the blow is struck in cushioning the parts. It thereby increases the force of the blow and also serves to regulate and govern the magnetic attraction. It likewise prevents the plunger from being accidentally forced back against the driving means for the sleeve and injuring the same.

.After the supply of current has been shut off from the motor the momentum of the driving mechanism will cause the sleeve to be reciprocated several times. As the magnetic attraction between the sleeve and plungcr has ceased, if it happens that the machine is being used in an inverted position with the drill upward, the driving apparatus is likely to be injured by the plunger. The air cushion prevents this.

As modifications of the novel devices, constructions and arrangements will readily suggest themselves to those skilled in this art, I do not limit myself to the several particulars shown and described, except as the same are made limitations on certain of the claims herein. It is obvious, furthermore, that certain of these devices, constructions and arrangements might be applied toforms of electromechanical apparatus other than the rock drill shown and described herein.

I claim:

1. In a device of the character described, the combination with a driving element, of a driven element and a magnet for maintaining the latter element in floating and elastic relation with the former; one of said elements comprising a cylinderclosed at one end and the other element being fitted into said cylinder so that a relative movement between said elements results in a compression of air between the same which modifies the effect of said magnet.

2. In a device of the character described, the combination with a driving element, of a driven element and a magnet for maintaining the latter element in floating and elastic relation with the former; one of said ele ments comprising a cylinder closed at one end and the other element. being fitted into said cylinder so that a relative movement between said elements results in a compression of air between the same which modifies the effector said magnet, said cylinder being formed with a vent.

3. In a device of the character described, the combination with a sleeve, a plunger titted within said sleeve, means for recipro eating the sleeve, means for producing a magnetic connection between said plunger and sleeve, and means which closes one end of the sleeve so as toprovide an air cushion which supplements the magnetic connection between said plunger and sleeve.

4. In a device of the character described, the combination with a sleeve, a plunger fitted within said sleeve, means for reciproeating the sleeve, and means for producing magnetic connection between said plunger and sleeve, said plunger being formed at one end with a striking part and said sleeve being closed atthe other end so as to provide an air cushion which supplements the mag netic connection between said plunger and sleeve when the plunger strikes its blow.

5. In a device of the character described, the combination with driving means, 01 a sleeve connected therewith at one end, a plunger in said sleeve, means which closes the sleeve at the end connected with the driving means, and means for producing a magnetic connection between said plunger and sleeve, comprising a magnet which is stationary relative to said sleeve and plunger, and which surrounds the same, said sleeve being formed with a vent in the side and a slot, substantially as described.

6. In a device of the character described, the combination with driving means, of a sleeve, a plunger in said sleeve, a coil which is stationary with respect to the sleeve and the plunger, a casing inclosing said coil, and a tool-holding nose-piece provided with an integrally formed ring which screws into said casing and constitutes a pole piece for said-coil.

7. In a device of the character described, the combination wit-h driving means, of a sleeve, :1 plunger in said sleeve, a coil which is stationary with respect to the sleeve and the plunger, a casing inclosing said coil, and a tool-holdingnose-piece provided with an integrally formed ring which screws into said casing and constitutes a pole piece for said coil, said ring having an annular exthe combination with driving ineans, of a sleeve, a plunger in said sleeve, a coil which is stationary with respect to the sleeve and the plunger, a casing lnclosing said 0011, a

tool-holdingnose-piece provided with an integrally formed ring which screws into said casing and constitutes a pole piecefiir said coil, said ring havingan annular extension which intervenes between the coil andsaid sleeve, and a pole piece at the other endott' said coil consisting of a ring having a siinilar integral entension.

9. In a device of the character described, the combination with a sleeve which is closed one end, means for reciprocating said sleeve, 21 plunger which is closely fitted H1 said sleeve so that an air cushion is provided between the plunger and the closed end of the sleeve, and means for providing a magnetic connection between said plunger and sleeve which sustains the former in fioating relation with the latter and out ofcontact with the closed end thereof.

, 10. In a device of the character described, the combination with a driving element, of a driven element and a magnet for maintaining the latter element in floating end elastic relation with the former; one of said elements comprising a cylinder closed 'at one end and the other element being fitted into said cylinder so that a relative movement between said elements results in a change in the air pressure between them which inedifies the e'tl'ect of said magnet.

snonen H. ROWE.

Witnesses i P H. TRUMAN, H, L. PEGK. 

